Metal insulator metal capacitor and method for making the same

ABSTRACT

A semiconductor device includes one or more metal-insulator-metal (MiM) capacitors. The semiconductor device includes a bottom electrode, a dielectric layer located above, and in physical contact with, the bottom electrode, a top electrode located above, and in physical contact with, the dielectric layer, a first top contact contacting the top electrode, a first bottom contact contacting the bottom electrode from a top electrode direction, a first metal bump connecting to the top contact, and a second metal bump connecting to the bottom contact. The top electrode has a smaller area than the bottom electrode. The bottom electrode, the dielectric layer, and the top electrode is a MiM capacitor. Top electrodes of a number of MiM capacitors and bottom electrodes of a number of MiM capacitors are daisy chained to allow testing of the conductivity of the electrodes.

This application is divisional application of U.S. patent applicationSer. No. 14/052,409, entitled “Metal Insulator Metal Capacitor andMethod for Making the Same,” filed on Oct. 11, 2013, which applicationsare incorporated herein by reference.

BACKGROUND

The semiconductor integrated circuit industry has experienced rapidgrowth in the past several decades. Technological advances insemiconductor materials and design have produced increasingly smallerand more complex circuits. These material and design advances have beenmade possible as the technologies related to processing andmanufacturing have also undergone technical advances. In the course ofsemiconductor evolution, the number of interconnected devices per unitof area has increased as the size of the smallest component that can bereliably created has decreased.

Metal-insulator-metal (MiM) capacitors are used in many applications onan integrated circuit (IC), including for signal conditioning. Duringthe operation of certain circuits, power supply lines may supplytransient currents with a relatively high intensity. These conditionscan result in noise on the power supply lines. Specifically, the voltageon the power supply line may fluctuate when the transition time of thetransient current is particularly short or when the line's parasiticinductance or parasitic resistance is large. To ameliorate suchconditions, filtering or decoupling capacitors may be used, acting astemporary charge reservoirs to prevent momentary fluctuations in supplyvoltage.

Integrating decoupling capacitors into certain systems-on-chip (SOCs)may entail a number of problems. For example, some decoupling capacitorsmay suffer from capacitance variations, delamination of conductors fromthe electrodes, or inadequate electrical coupling between the conductorand the electrodes. These capacitors may be integrated in themulti-level interconnect (MLI) at different levels. Before circuitdesign and a process for forming a circuit can be qualified formanufacturing, all devices including MiM capacitors should be tested toverify functionality.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isemphasized that, in accordance with the standard practice in theindustry, various features of the figures are not drawn to scale. Infact, the dimensions of the various features may be arbitrarilyincreased or reduced for clarity of discussion.

FIG. 1 is a cross-sectional diagram of a system-on-chip (SOC) thatincludes a metal-insulator-metal (MiM) capacitor;

FIG. 2 is a cross-sectional diagram of an SOC that includes a decouplingcapacitor areas and a logic area in a metal interconnect layer accordingto various embodiments of the present disclosure;

FIG. 3 is a cross-sectional diagram of a metal insulator metal (MiM)capacitor in accordance with various embodiments of the presentdisclosure;

FIGS. 4A and 4B are a cross-sectional diagram and a top view of some ofthe layers of a number of MiM capacitors according to variousembodiments;

FIGS. 4C and 4D are a cross-sectional diagram and a top view of some ofthe layers of a number of MiM capacitors according to variousembodiments;

FIG. 4E is a cross-sectional diagram of MiM capacitors having both thetop electrode and bottom electrode separated daisy chained in accordancewith various embodiments of the present disclosure;

FIG. 5 depicts a plurality of MiM decoupling capacitor types that may beused in some embodiments; and

FIGS. 6A-L are cross-sectional representations of a MiM decouplingcapacitor during various steps of fabrication.

The various features disclosed in the drawings briefly described abovewill become more apparent to one of skill in the art upon reading thedetailed description below. Where features depicted in the variousfigures are common between two or more figures, the same identifyingnumerals have been used for clarity of description.

DETAILED DESCRIPTION

It is to be understood that the following disclosure provides manydifferent embodiments and examples for implementing different featuresof the invention. Specific examples of components and arrangements aredescribed below to simplify the present disclosure. These are, ofcourse, merely examples and are not intended to be limiting. Moreover,the formation of a first feature over or on a second feature in thedescription that follows may include embodiments in which the first andsecond features are formed in direct contact, and may also includeembodiments in which additional features may be formed interposing thefirst and second features, such that the first and second features maynot be in direct contact. Various features in the figures may bearbitrarily drawn in different scales for the sake of simplicity andclarity.

FIG. 1 illustrates a system-on-chip (SOC) 100, which may include aplurality of functional areas fabricated on a single substrate. Asdepicted in FIG. 1, SOC 100 includes a logic area 110, a non-volatilememory (NVM) cell 130, and a decoupling capacitor area 150. Logic area110 may include circuitry, such as the exemplary transistor 112, forprocessing information received from non-volatile memory cell 130 andfor controlling reading and writing functions of NVM cell 130. In someembodiments, NVM cell 130 may be a resistive random-access memory (RRAM)cell, phase-change random-access memory (PCRAM) cell, magnetoresistiverandom-access memory (MRAM) cell, or a transistor based random-accessmemory such as flash memory or static random-access memory (SRAM). AnNVM cell may be used to hold a binary piece of data, or a bit. Dependingon the type of memory cell, NVM 130 may include a pair ofmetal-insulator-metal (MiM) structures 140. Each MiM structure 140 mayinclude a bottom electrode 142 and top electrode 146, with a dielectriclayer 144 sandwiched in between the two electrodes.

Decoupling capacitor area 150, as depicted, includes a MiM decouplingcapacitor 152 may be fabricated simultaneously with MiM structures 140.For example, after M4 has been patterned and IMD4 has been deposited,SOC 100 undergoes a planarization process, such as chemo-mechanicalplanarization (CMP). After the CMP process, a bottom electrode 154 isdeposited overlaying IMD4 and the exposed portions of M4. The bottomelectrode 154 may be any of a variety of materials; specifically, bottomelectrode materials may include Pt, AlCu, TiN, Au, Ti, Ta, TaN, W, WN,and Cu. Generally, the bottom electrode materials are conductivematerials such as metals, certain metal nitrides, and silicided metalnitrides. The dielectric layer 156 is formed from an insulatingmaterial, including but not limited to NiO, TiO, HfO, ZrO, ZnO, WO₃,Al₂O₃, TaO, MoO, and CuO. The insulating material may be a highdielectric constant (high-k) material, which may include TiO₂, Ta₂O₅,Y₂O₃, La₂O₅, HfO₂, and other materials. The top electrode 158 may befabricated of any of the same materials as bottom electrode 154, asdescribed above, though the same material is not necessarily used forboth the top and bottom electrodes. The substrate surface area of MiMdecoupling capacitor area 150 may include SOC logic, including exemplarylogic transistor 160. A single mask may be used to form MiM structures140 and MiM decoupling capacitor 152.

The SOC 100 also includes shallow-trench isolation (STI) features, andpluralities of metallization layers and vias. As depicted, SOC 100 isfabricated using five metallization layers, labeled as M1 through M5,with five layers of metallization vias or interconnects, labeled as V1through V5. Other embodiments may contain more or fewer metallizationlayers and a corresponding more or fewer number of vias. Logic area 110includes a full metallization stack, including a portion of each ofmetallization layers M1-M5 connected by interconnects V2-V5, with V1connecting the stack to a source/drain contact of logic transistor 112.NVM cell 130 includes a full metallization stack connecting MiMstructures 140 to memory cell transistors 132. MiM structures 140 aredepicted as being fabricated in between the top of the M4 layer and thebottom the M5 layer. Also included in SOC 100 is a plurality ofinter-metal dielectric (IMD) layers. Six IMD layers, identified as IMD0through IMD5 are depicted in FIG. 1 as spanning the logic area 110, RRAMcell 130, and decoupling capacitor area 150. The IMD layers may provideelectrical insulation as well as structural support for the variousfeatures of SOC 100 during many fabrication process steps, some of whichwill be discussed herein.

The decoupling capacitor 152 may be used by SOC 100 to condition powersupply lines that supply current to charge and discharge active andpassive devices included in SOC 100. When voltages swing during a clocktransition, fluctuations on the power supply lines may introduce noise.Decoupling capacitor 152 acts as a charge reservoir to smooth out acertain amount of the introduced noise.

The MiM capacitors 140 and 152 of FIG. 1 are connected from top to a topelectrode and from the bottom from a bottom electrode. Functionaltesting of the MiM capacitor structure is routed through the entirecircuit, for example, the memory cell 130. It is difficult todistinguish issues of the circuit to a specific portion, for example,the MiM capacitor, the transistor, or the intervening interconnectstructure. During process and package development, the ability toseparately test MiM capacitor structures is beneficial to pinpointproblem areas, for example, delamination of the metal contact to one ormore of the MiM capacitor electrodes, the dielectric layer between theelectrodes, or short circuits through other features. The presentinvention pertains to a MiM capacitor structure to be used in a testvehicle to detect and pinpoint failures in the MiM capacitor structureand a process for testing the MiM capacitors.

FIG. 2 includes a MiM capacitor structure cross-section 201 in adecoupling capacitor area 250 and an interconnect structure in a logicarea 260 in an SOC 200 according to various embodiments. The MiMcapacitor 201 includes a top electrode 203 over a dielectric layer 205over a bottom electrode 207. The top electrode 203 has a smaller areathan the bottom electrode 207. The top electrode 203 directly contacts atop contact 209. A first passivation layer 213 surrounds an interfacebetween the top contact 209 and the top electrode 203 and may cover theentire top electrode 203. A second passivation layer 215 covers thefirst passivation layer 213 and portions of the dielectric layer 205where the top electrode 203 does not cover the dielectric layer 205. Abottom contact 211 contacts the bottom electrode 207 through thedielectric layer 205 from a same direction as the top contact 209. Thetop contact 209 and the bottom contact 211 are both connected todifferent conductive bumps (not shown). The conductive bumps may belocated directly above the metal layer Mz when the MiM capacitor islocated in the top electrode layer or there may be one or moreintervening metal layers.

In the logic area 260 of FIG. 2, the metal line 202 and conductive via204 are located in the same metal layer as the MiM capacitor and the topand bottom contacts. Conductive via 204 is connected to another metalline 206 in the metal layer Mz−1 or Mx immediately below the metal layerMz.

By connecting to the bottom electrode 207 through the top as opposed tothe bottom as shown in FIG. 1, the electrical properties of the bottomelectrode 207 and the MiM capacitor 201 can be easily tested. In oneexample, capacitance is measured across the conductive bumps through thetop contact 209 and the bottom contact 211 to verify the MiM capacitor201 works as intended.

According to various embodiments, more than one top contact and morethan one bottom contact may be used to connect to the top and bottomelectrodes. FIG. 3 is a cross sectional diagram of a MiM capacitor 300having top contacts 301 and 303 connected to the top electrode 305 andbottom contacts 307 and 309 connected to the bottom electrode 311. Thebottom contacts 307 and 309 extend through openings in the top electrode305. The top contacts 301 and 303 extend through openings in the bottomelectrode 311 to metal lines 317 and 319. As shown in FIG. 3, the bottomcontacts 307 and 309 extend through the bottom electrode 311 to metallines 321 and 323 below. In some embodiments, the various contacts donot extend to metal lines below.

Arrows 313 and 315 shows the conductive path through the top electrode305 and the bottom electrode 311, respectively. Each of the top contacts301 and 303 and bottom contacts 307 and 309 is connected to conductivebumps and may be used to test various electrical properties of the MiMcapacitor 303. The top conductive path 313 may be used alone to test aresistance across the top electrode 305 to ensure no delaminationbetween the top electrode 305 and top contacts 301 and 303 has occurred.The bottom conductive path 315 may be used alone to test a resistanceacross the bottom electrode 311 to ensure no delamination between thebottom electrode 311 and the bottom contacts 307 and 309 has occurred.Even though as drawn the arrow line 315 appears to cross openings in thebottom electrode 311, the entire bottom electrode 311 is conductivethrough contiguous portions. In other words, the openings in the bottomelectrode 311 to accommodate the top contacts 301 and 303 do notseparate the bottom electrode into more than one piece. In a top view,the bottom electrode 311 appears as a geometric shape, for example, arectangle, with two openings in the middle. Capacitance may be measuredacross the MiM capacitor 300 using one of the top contacts 301/303 andone of the bottom contacts 307/309.

According to various embodiments of the present disclosure, multiple MiMcapacitors may be connected together to test the top electrodes and/orthe bottom electrodes of the multiple MiM capacitors without using twoexternal bumps per electrode. FIGS. 4A, 4C, and 4E are cross sectionaldiagrams of MiM capacitor structures having three MiM capacitors with aninternal contact or interconnection between adjacent MiM capacitors.FIG. 4B is a top view of some of the layers in the cross sectionalstructure of FIG. 4A. FIG. 4D is a top view of some of the layers in thecross sectional structure of FIG. 4C. The structure 400 of FIGS. 4A and4B may be used to daisy chain top electrodes of different MiMcapacitors. The structure 450 of FIGS. 4C and 4D may be used to daisychain bottom electrodes of different MiM capacitors. In someembodiments, the structures 400 and 450 of FIGS. 4A/4B and 4C/4D aredifferent cross sections of a set of MiM capacitors arranged in an arrayso that both the top electrodes and the bottom electrodes of the set ofMiM capacitors are daisy chained respectively. The structure 480 of FIG.4E is yet another embodiment where a metal level below is used to daisychain the bottom electrodes of adjacent MiM capacitors.

FIGS. 4A and 4B include three MiM capacitors 401, 402, and 403 havingtop electrodes daisy-chained together. Each of the MiM capacitors 401,402, and 403 includes a top electrode 401A, 402A, and 403A, a dielectriclayer 401B, 402B, and 403B, and a bottom electrode 401C, 402C, and 403C,respectively. Top electrode contacts 404 and 405 connect the topelectrodes 401A and 403A to redistribution layers 406 and 407,respectively, which are connected to under bump pads 408 and 409,respectively. The bumps 410 and 411 are disposed over the under bumppads 408 and 409 and are thus connected to the top electrodes 401A and403A respectively. Top contact interconnect 412 connects the topelectrode 401A to the top electrode 402A. Top contact interconnect 413connects the top electrode 402A to the top electrode 403A.

FIG. 4B includes a cutline A-A′ from which the cross sectional diagramof FIG. 4A is viewed. FIG. 4B is a simplified version of a layout ofstructure 400 with only the bottom electrodes, top electrodes,top/bottom contacts, and bumps shown. Other layers in FIG. 4A such asthe under bump pad, redistribution layer, passivation layer, and thedielectric layer are not included.

A current path between the bumps 410 and 411 routes from the bump 410,under bump pad 408, redistribution layer 406, top contact 404, topelectrode 401A of the MiM capacitor 401, top contact interconnect 412,top electrode 402A of the MiM capacitor 402, top contact interconnect413, top electrode 403A of the MiM capacitor 403, top contact 405,redistribution layer 407, under bump pad 409, to the bump 411. Thecurrent path thus daisy chains the top electrodes of MiM capacitors 401,402, 403 together. A resistance across this current path can be measuredto determine whether the features along the path are electricallyconnected as expected.

FIG. 4A also includes contacts and bumps connected to bottom electrodes.The bottom electrode 402C is connected to a bottom contact 414, which isconnected to redistribution layer 415, under bump pad 416, and bump 417.The bottom contact 414 connects to the bottom electrode 402C through anopening in the top electrode 402A of the MiM capacitor 402. As shown inFIG. 4B, the opening in the top electrode 402A of the MiM capacitor 402does not run an entire length of the MiM capacitor 402, the topelectrode 402A on either side of the opening is still electricallyconnected. Similarly, the bottom electrode 403C is connected to a bottomcontact 418, which is connected to redistribution layer 419, under bumppad 420, and bump 421. The bottom contact 418 connects to the bottomelectrode 403C through an opening in the top electrode 403A of the MiMcapacitor 403. The bumps 410 and 417 may be used to measure acapacitance of the MiM capacitors 401 and 402. The bumps 410 and 421 maybe used to measure a capacitance of the MiM capacitors 401, 402, and403. The bumps 411 and 421 may be used to measure a capacitance of theMiM capacitor 403. In some embodiments, the bottom electrode 401C may beseparately connected to an external bump to isolate the MiM capacitor401 for a capacitance measurement. One may design a MiM capacitorstructure having a number of MiM capacitors that allows measurement andisolation of faults. A measurement may be compared to an expected value.

In the structure 400 of FIG. 4A, features below the redistribution layer(406, 415, 407, 419) are embedded in a dielectric passivating material422. The dielectric material 422 may include one or more layers ofdielectrics including silicon oxide, silicon nitride, silicon carbide,silicon oxynitride, carbon-doped silicon oxide, carbon-doped siliconnitride, and other commonly used dielectric material in semiconductorprocessing.

In some embodiments, the bottom electrode contacts 414, 418 andrespective bumps 417, 421, under bump pad 415, 420, and redistributionlayer 415, 419 are not included in the structure 400. In theseembodiments, the structure 400 minimizes the number of bumps used on thesurface, reduces the size of the MiM capacitors, and allows the MiMcapacitors to be close together. Structure 400 is used to verify theintegrity of the top electrodes 401A, 402A, and 403A. For example, theMiM capacitor 402 may be small and has room for only two contacts to beformed over the MiM capacitor 402. A separate structure may be used totest the performance of the MiM capacitors.

FIG. 4C is a cross section diagram of a MiM capacitor structure 450including three MiM capacitors 451, 452, and 453 having bottomelectrodes daisy-chained together. FIG. 4D is a top view of some of thelayers in the cross sectional structure of FIG. 4C. Each of the MiMcapacitors 451, 452, and 453 includes a bottom electrode 451C, 452C, and453C, a dielectric layer 451B, 452B, and 453B, and a top electrode 451A,452A, and 453A, respectively. Bottom electrode contacts 454 and 455connect the bottom electrodes 451A and 453A to redistribution layers 456and 457, respectively, which is connected to under bump pads 458 and459, respectively. The bumps 460 and 461 are disposed over the underbump pads 458 and 459 and are thus connected to the bottom electrodes451C and 453C respectively. Bottom contact interconnect 462 connects thebottom electrode 451C to the bottom electrode 452C. Bottom contactinterconnect 463 connects the bottom electrode 452C to the bottomelectrode 453C.

FIG. 4D includes a cutline B-B′ from which the cross sectional diagramof FIG. 4C is viewed. FIG. 4D is a simplified version of a layout ofstructure 450 with only the bottom electrodes, top electrodes,top/bottom contacts, and bumps are shown. Other layers in FIG. 4C suchas the under bump pad, redistribution layer, passivation layer, and thedielectric layer are not included.

A current path between the bumps 460 and 461 routes from the bump 460,under bump pad 458, redistribution layer 456, bottom contact 454, bottomelectrode 451C of the MiM capacitor 451, bottom contact interconnect462, bottom electrode 452C of the MiM capacitor 452, bottom contactinterconnect 463, bottom electrode 453C of the MiM capacitor 453, bottomcontact 455, redistribution layer 457, under bump pad 459, to the bump461. The current path thus daisy chains the bottom electrodes of MiMcapacitors 451, 452, 453 together. A resistance across this current pathcan be measured to determine whether the features along the path areelectrically connected as expected.

FIG. 4C also includes contacts and bumps connected to top electrodes.The top electrode 452A is connected to a top contact 464, which isconnected to redistribution layer 465, under bump pad 466, and bump 467.Similarly, the top electrode 453A is connected to a top contact 468,which is connected to redistribution layer 469, under bump pad 470, andbump 471. The bumps 460 and 467 may be used to measure a capacitance ofthe MiM capacitors 451 and 452. The bumps 460 and 471 may be used tomeasure a capacitance of the MiM capacitors 451, 452, and 453. The bumps461 and 471 may be used to measure a capacitance of the MiM capacitor453. In some embodiments, the top electrode 451A may be separatelyconnected to an external bump to isolate the MiM capacitor 451 for acapacitance measurement.

In the structure 450 of FIGS. 4C and 4D, features below theredistribution layer (456, 465, 457, 469) are embedded in a dielectricpassivating material 472. The dielectric material 472 may include one ormore layers of dielectrics including silicon oxide, silicon nitride,silicon carbide, silicon oxynitride, carbon-doped silicon oxide,carbon-doped silicon nitride, and other commonly used dielectricmaterial in semiconductor processing.

In some embodiments, the top electrode contacts 464, 468 and respectivebumps 467, 471, under bump pad 466, 470, and redistribution layer 465,469 are not included in the structure 450. In these embodiments, thestructure 450 minimizes the number of bumps used on the surface, reducesthe size of the MiM capacitors, and allows the MiM capacitors to beclose together. Structure 450 is used to verify the integrity of thebottom electrodes 451A, 452A, and 453A. For example, the MiM capacitor452 may be small and has room for only two contacts to be formed overthe MiM capacitor 452. A separate structure may be used to test theperformance of the MiM capacitors.

According to some embodiments, structures 400 and 450 of FIGS. 4A/4B and4C/4D may reflect different cross sections in an array of MiMcapacitors. For example, MiM capacitor structures 401 and 451 of FIGS.4A and 4C may be the same MiM capacitors. The top contact interconnectsand the bottom contact interconnects may be in the same MiM capacitorarray so that a variety of electrical tests may be performed. WhileFIGS. 4A/4B and 4C/4D includes only three MiM capacitors, an array ofdifferent numbers of MiM capacitors may be used according to conceptsdisclosed herein. For example, a daisy chain may include 2 to 10 topelectrodes.

In some embodiments, the bottom contact interconnect may be formed in ametal layer below the MiM capacitors. FIG. 4E includes a structure 480with bottom contact interconnects 481 and 482 in a metal layer below theMiM capacitors 491, 492, and 493. Structure 480 reduces the number ofvia landings on or over the MiM capacitors 491, 492, and 493, which maybe useful when the MiM capacitors are small. As shown, structure 480includes bumps 483-486. Bump 483 is connected to a bottom electrode ofthe MiM capacitor 491. Bump 484 is connected to a top electrode of theMiM capacitor 491. Bump 485 is connected to a top electrode of the MiMcapacitor 493. Bump 486 is connected to a bottom electrode of the MiMcapacitor 493. A resistance may be measured across bumps 484 and 485 orbumps 483 and 486 to determine electrical connectivity of theintervening features. Capacitance may be measured between 484 and 486 or483 and 485 for MiM capacitors 491, 492, and 493.

In some embodiments, one or more of the top electrode contacts and thebottom electrode contacts may extend through the MiM capacitor structureto a layer below. This design allows the same bump to be used for morethan one type of test. For example, the bump may also be connected to amemory cell or logic circuit below the MiM capacitor which may be testedthrough output to different bumps.

Various embodiments of the invention are applicable to MiM capacitors ofdifferent configurations and are not limited to the planar MiMcapacitors shown in FIGS. 1 to 4C. One skilled in the art may apply theconcepts disclosed to various types of MiM capacitor structures. FIG. 5depicts some types of MiM capacitive structures, including a planar-typeMiM structure 502, a cylinder- or cup-type MiM structure 504, a bar-typeMiM structure 506, and a dual-damascene MiM structure 508, which is aMiM structure formed by a dual-damascene process. Each of these MiMcapacitor structures includes a top and a bottom electrode on eitherside of a dielectric layer. As discussed, a planar-type MiM structure502 includes a bottom electrode 502A, a dielectric layer 502B, and a topelectrode 502C sandwiched together. Cylinder-type MiM structure 504 hasa rectangular cross-section when viewed from the side as in FIG. 5. Whenviewed from above, it has a circular cross-section. As depicted in FIG.5, cylinder-type MiM structure 504 may include a gap 510 in the topelectrode 504C, a dielectric layer 504B under the top electrode 504C,and a bottom electrode 504A. In some embodiments, gap 510 is present asdepicted, while in others gap 510 is absent. MiM capacitor structure 506is a bar-type capacitor with a top electrode 506C, a dielectric layer506B and a bottom electrode 506A. MiM decoupling capacitor 508 is adual-damascene MiM structure 508 with a top electrode 508C, a dielectriclayer 508B and a bottom electrode 508A.

Different process techniques can be used to fabricate the above-listedMiM capacitors. FIGS. 6A-L are cross-sectional representations of adevice 600, which may be similar in many respects to the MiM capacitorSOC 200 discussed in association with FIG. 2. FIG. 6A includes a logicarea 601 and a decoupling capacitor area 603. Each of these two areasincludes a portion of a substrate and of intermediate layer.Intermediate layer includes a plurality of semiconductor device layersthat, for convenience and clarity, are not individually shown. Theintermediate layer may include polysilicon gate and contact layers, gateand other oxide layers, interconnects between metallization layers,metallization layers, IMD layers, and others. Thus, for example,intermediate layer includes a first metal layer to a metal layerimmediately below the top metal layer and all layers embedded therein.The device 600 cross-section in FIG. 6A also includes a plurality ofmetallization layer contact areas embedded in a metal layer 602. Asshown, the plurality includes metallization layer contact areas 606A,606B, 606C, and 606D which may have been patterned prior to thedeposition of passivation layers 605 and 607. In some embodiments, afirst passivation layer 605 of silicon carbide is deposited over aplanarized surface of metal contact areas 606A, 606B, 606C, and 606D. Asecond passivation layer 607 of silicon oxide is deposited over thefirst passivation layer. The first passivation layer 605 may be about500 angstroms and the second passivation layer 607 may be about 1000angstroms.

FIG. 6B includes a bottom conductive layer 609, a dielectric layer 611,a top conductive layer 613, and a hardmask layer 615. The bottomconductive layer may be formed of many different materials, and mayinclude a plurality of layers of a single material or of differentmaterials. In general, bottom conductive layer 609 can be made of metalsand conductive metal nitrides, for example, titanium nitride, though anysuitable conductor may be used. Bottom conductive layer 609 may befabricated using a variety of deposition processes, including vapordeposition processes, filament evaporation, e-beam evaporation, andsputtering. Any suitable deposition process may be used to form thebottom conductive electrode layer 609. In some embodiments, the bottomconductive layer may be between about 200 and 500 angstroms, forexample, about 350 angstroms.

Device 600 also includes an insulating layer or dielectric layer 611.The insulating dielectric layer 611 is formed over the bottom conductiveelectrode layer 609. In general, the insulating layer may be formed ofan insulating material, including the specific materials already noted.These materials may include high-k dielectrics, for example, zirconiumoxide. Suitable processes include chemical vapor depositions (CVD), suchas low-pressure CVD (LPCVD), plasma-enhanced CVD (PECVD), and atomiclayer deposition. In general, any suitable process for depositing thedielectric layer may be used. In some embodiments, the dielectric layer611 is about 100 angstroms.

Device 600 includes a top conductive layer 613 overlaying the dielectriclayer 611. While the top conductive layer 613 may include a differentmaterial or materials from bottom conductive layer 609, the kinds ofmaterials from which, and processes by which, top conductive layer 613may be made are substantially the same as those of bottom conductivelayer 609. Any of those processes or materials may be used to form thetop conductive layer 613. Overlaying the top conductive layer 613 is afirst hardmask layer 615, which may be a silicon nitride, silicon oxide,or silicon oxynitride. According to various embodiments, a photoresist(PR) layer is used over the first hardmask layer. A PR layer may be usedover the first hardmask layer to pattern it before etching the topconductive layer 613. The etching process may be a wet chemical etchingwith a variety of chemical etchants or may also be a physical or dryetching process such as plasma etching, sputter etching, reactive ionetching or vapor phase etching.

In FIG. 6C, after an etching process, the first hardmask layer 615 hasbeen patterned so as the form an etch mask and a top electrodes 623 isetched under the first hardmask layer 615. Top electrode 623 functionsas a top electrode in a MiM structure, for example, a MiM decouplingcapacitor. In the logic area 601, the top conductive layer is removed.

In FIG. 6D, a second hardmask layer 617 is deposited over the substrate.The second hardmask layer 617 covers the first hardmask layer 615, thesidewalls of the top electrode 623, and over exposed portions of thedielectric layer 611. The second hardmask layer 617 may be siliconnitride or silicon oxide. In some embodiments, the second hardmask layer617 is a silicon nitride about 500 angstroms thick.

In FIG. 6E, the first passivation layer 617 is patterned and etchedthrough the underlying dielectric layer and bottom conductive layer tothe second passivation layer 607. The resulting device 600 includes adielectric layer 621 and a bottom electrode 619. The top electrode 623,the dielectric layer 621, and the bottom electrode 619 together formsthe MiM capacitor 625.

In FIG. 6F, a third passivation layer 627 is deposited over thesubstrate. The third passivation layer 627 may be a same material as thesecond passivation layer 607. In some embodiments, the third passivationlayer 627 is a silicon oxide having a thickness of about 10,000angstroms, or about 900 angstroms. The third passivation layer 627 isthen planarized as shown in FIG. 6G.

As shown in FIG. 6H, additional passivating material is deposited overthe third passivation layer 627. A third hardmask layer 629 is depositedover the third passivation layer 627. A fourth passivation layer 631 isdeposited over the third hardmask layer 629. A fourth hardmask layer 633is deposited over the fourth passivation layer 631. The third and fourthhardmask layers and the fourth passivation layer are deposited togetherwith dual damascene processing in the logic area and elsewhere on thedevice 600. In some embodiments, the third hardmask layer 629 is asilicon nitride having a thickness of about 500 angstroms. The fourthpassivation layer 631 is a silicon oxide having a thickness of about10000 angstroms, or about 9000 angstroms. The fourth hardmask layer 633is a silicon oxynitride having a thickness about 500 angstroms or about600 angstroms.

In FIG. 6I, openings 635, 637, and 639 are made in the device 600 bypatterning the fourth hardmask layer 633 and etching through the fourthpassivation layer 631, the third hardmask layer 629, and the thirdpassivation layer 627. The opening 635 lands on the second hardmasklayer 617 above the top electrode 623. The opening 637 lands on thesecond hardmask layer 617 above the dielectric layer 621. The opening639 lands on the first passivation layer 605. Because the openings 635,637, and 639 have different depths, one or more etch end pointdetections may be used to detect when the second hardmask layer 617 isreached. Thereafter, the etch may proceed until the first passivationlayer 605 is detected. In some embodiments, the first passivation layer605 is silicon carbide, which is different from the second hardmasklayer 617 of silicon nitride. In other embodiments, the second hardmasklayer 617 and the first passivation layer 605 are of the same material,which is designed to have a higher etch selectivity than the overlyingthird passivation layer 627. The etch process may be tuned to proceed acertain amount after detecting the second hardmask layer 617 so that thesecond hardmask layer 617 is not etched through.

In FIG. 6J, a photoresist 646 is deposited in the openings and etchedback to protect the via portions of the contacts. The etch back processforms openings 641, 643, and 645 have about the same depth. Theremainder portions of the openings 635, 637, and 639 of FIG. 6I arefilled with the photoresist material 646.

In FIG. 6K, trenches 647, 649, and 651 are etched about the openings641, 643, and 645 from FIG. 6J in a damascene process. The etch processalso removes the photoresist material 646 and extends the openings 641,643, and 645 to reach conductive layers below. One or more etch pointdetections may be used to detect titanium nitride and copper. When oneconductive material is detected, the etch may proceed slowly until thesecond conductive material is detected. The trenches 647 and 649 areused to form contacts to the MiM capacitor 625. A via portion belowtrench 647 exposes the top electrode 623. A via portion below trench 649exposes the bottom electrode 619. A via portion below trench 651 exposesan underlying metal line 606D.

In FIG. 6L, the trench and via portions are filled with a conductivematerial, usually copper to form contacts 653, 655, and 657. Contact 653is a top contact. Contact 655 is a bottom contact. Contact 657 connectsto metal line 606D in the logic area. The device 600 of FIG. 6L is thesame as the SOC 200 of FIG. 2. After forming the device 600 of FIG. 6L,additional metal layers may be formed over the contacts 653, 655, and657 or, if the contacts 653, 655, and 657 are in the top metal layer,then a redistribution layer, under bump pad, and bumps may be formedover the contacts 653, 655, and 657.

The process used to form the cross section diagrams of FIGS. 6A to 6Lmay be modified to form the MiM capacitor structures of FIGS. 3 and 4Ato 4C. For the structure 300 of FIG. 3, an addition patterning andetching operation is added after depositing the bottom conductive layer609 of FIG. 6B to create openings in the bottom electrode for the topcontacts to reach the metal lines below. The etch operation to form theopenings 635, 637, and 639 is adjusted so that openings 635 and 637reaches the underlying metal lines by reducing the thickness of hardmask617 in FIG. 6I. The structure 400 of FIG. 4A and structure 450 of FIG.4B may be formed using the process described in association with FIGS.6A to 6L by merely changing the photomask layout. The structure 480 ofFIG. 4C may be formed by first forming conductive via structures throughthe first and second passivation layers 605 and 607 in FIG. 6A beforeany conductive layers are deposited in FIG. 6B.

In one aspect, the present disclosure pertains to a semiconductordevice. The semiconductor device includes a bottom electrode, adielectric layer located above, and in physical contact with, the bottomelectrode, a top electrode located above, and in physical contact with,the dielectric layer, a first top contact contacting the top electrode,a first bottom contact contacting the bottom electrode from a topelectrode direction, a first metal bump connecting to the top contact,and a second metal bump connecting to the bottom contact. The topelectrode having a smaller area than the bottom electrode. The bottomelectrode, the dielectric layer, and the top electrode is a firstmetal-insulator-metal (MiM) capacitor. The semiconductor device may alsoinclude one or more second MiM capacitor with corresponding top contactsand top electrode interconnects between adjacent top electrodes ofadjacent MiM capacitors.

In another aspect, the present disclosure pertains to a semiconductordevice. The semiconductor device includes a bottom electrode, adielectric layer located above, and in physical contact with, the bottomelectrode, a top electrode located above, and in physical contact with,the dielectric layer, a first top contact contacting the top electrode,a first bottom contact contacting the bottom electrode from a topelectrode direction through the openings in the top electrode, a firstmetal bump connecting to the top contact, a second metal bump connectingto the bottom contact, and at least one of a second top contactcontacting the top electrode and a second bottom contact contacting thebottom electrode. The bottom electrode, the dielectric layer, and thetop electrode is a first metal-insulator-metal (MiM) capacitor.

In yet another aspect, the present disclosure pertains to a method fortesting MiM capacitors. The method includes forming a first MiMcapacitor, forming a first top contact in contact with a top electrodeof the first MiM capacitor, forming a first bottom contact in contactwith a bottom electrode of the first MiM capacitor through an opening ofthe top electrode of the first MiM capacitor, forming metal bumps overthe first top contact and the first bottom contact, and measuringelectrical properties of the first MiM capacitor through the metalbumps. Additionally, resistance across several top electrodes may bemeasured by daisy-chaining the top electrodes of adjacent MiM capacitorsand resistance across several bottom electrodes may be measured bydaisy-chaining the bottom electrodes of adjacent MiM capacitors. Themeasurements may be compared and analyzed to localize a manufacturingissue.

In yet another aspect, the present disclosure pertains to a method forforming a semiconductor device. The method includes forming a bottomelectrode over a substrate, forming a capacitor dielectric over thebottom electrode, and forming a top electrode over the capacitordielectric, the bottom electrode, the capacitor dielectric, and the topelectrode forming a first MiM capacitor. A plurality of one and at leastone of the other of (a) first top conductive features in contact withthe top electrode of the first MiM capacitor and (b) first bottomconductive features in contact with the bottom electrode of the firstMiM capacitor are formed. A metal bump is formed over at least one ofthe first top and bottom conductive features.

In yet another aspect, the present disclosure pertains to a method forforming a semiconductor device. The method includes forming a pluralityof MiM capacitors, each of the MiM capacitors having a bottom electrode,a top electrode, and a dielectric layer interposed between the bottomelectrode and the top electrode, each of the bottom electrodes beingdiscontinuous from the bottom electrodes of other MiM capacitors. One ormore bottom contact interconnects are formed, each bottom contactinterconnect electrically coupling bottom electrodes of adjacent MiMcapacitors, the one or more bottom contact interconnects beingcompletely covered by a dielectric material. A first top contact isformed electrically coupled to a first top electrode of a first MiMcapacitor of the plurality of MiM capacitors, and a first bottom contactis formed contacting at least one of the bottom electrodes from a topelectrode direction, the first bottom contact being distinct from theone or more bottom contact interconnects.

In yet another aspect, the present disclosure pertains to a method forforming a semiconductor device. The method includes forming a first MiMcapacitor over a substrate, forming a second MiM capacitor over thesubstrate, each of the first MiM capacitor and the second MiM capacitorhaving a top electrode and a bottom electrode, and forming a dielectriclayer over the first MiM capacitor and the second MiM capacitor. Aplurality of first vias through the dielectric layer to one of the topelectrode of the first MiM capacitor and the bottom electrode of thefirst MiM capacitor, and a single second via is formed to the other ofthe top electrode of the first MiM capacitor and the bottom electrode ofthe first MiM capacitor.

The foregoing has outlined features of several embodiments so that thoseskilled in the art may better understand the detailed description. Thoseskilled in the art should appreciate that they may readily use thepresent disclosure as a basis for designing or modifying other processesand structures for carrying out the same purposes and/or achieving thesame advantages of the embodiments introduced herein. Those skilled inthe art should also realize that such equivalent constructions do notdepart from the spirit and scope of the present disclosure, and thatthey may make various changes, substitutions, and alterations hereinwithout departing from the spirit and scope of the present disclosure.

What is claimed is:
 1. A method for forming a semiconductor device, themethod comprising: forming a bottom electrode over a substrate; forminga capacitor dielectric over the bottom electrode; forming a topelectrode over the capacitor dielectric, the bottom electrode, thecapacitor dielectric, and the top electrode forming a first MiMcapacitor; forming a plurality of one and at least one of the other of(a) first top conductive features in contact with the top electrode ofthe first MiM capacitor and (b) first bottom conductive features incontact with the bottom electrode of the first MiM capacitor, theforming the first top conductive features and the first bottomconductive features comprising: forming one or more first dielectriclayers over the top electrode; forming at least one first opening to thetop electrode and at least one second opening to the bottom electrode;forming a second dielectric layer in a lower portion of the firstopening and the second opening, an upper surface of the seconddielectric layer being recessed from an upper surface of the one or morefirst dielectric layers; widening an upper portion of the first openingand the second opening while the second dielectric layer is in the lowerportion of the first opening and the second opening; removing the seconddielectric layer from the first opening and the second opening; andfilling the first opening and the second opening with a conductivematerial; and forming a metal bump over at least one of the first topand bottom conductive features.
 2. The method of claim 1, wherein theforming the plurality of one and at least one of the other comprisesforming a plurality of first bottom conductive features, the pluralityof first bottom conductive features extending through openings in thetop electrode of the first MiM capacitor.
 3. The method of claim 1,wherein the first MiM capacitor comprises a first MiM feature and asecond MiM feature, each of the first MiM feature and the second MiMfeature having a top conductive layer, a bottom conductive layer, and adielectric layer interposed between the top conductive layer and thebottom conductive layer, the top conductive layer of the first MiMfeature being discontinuous from the top conductive layer of the secondMiM feature, the bottom conductive layer of the first MiM feature beingdiscontinuous from the bottom conductive layer of the second MiMfeature.
 4. The method of claim 3, further comprising forming a firstinterconnect over the top electrode, the first interconnect coupling thetop conductive layer of the first MiM feature to the top conductivelayer of the second MiM feature.
 5. The method of claim 3, furthercomprising forming a second interconnect below the bottom electrode, thesecond interconnect coupling the bottom conductive layer of the firstMiM feature to the bottom conductive layer of the second MiM feature. 6.The method of claim 1, wherein the bottom electrode comprises one ormore of a plurality of discontinuous sections of a conductive layer, andfurther comprising forming one or more interconnects coupling adjacentones of the plurality of discontinuous sections of the conductive layer.7. The method of claim 1, wherein the top electrode comprises one of aplurality of discontinuous sections of a conductive layer, and furthercomprising forming one or more interconnects coupling adjacent ones ofthe plurality of discontinuous sections of the conductive layer.
 8. Themethod of claim 1, further comprising measuring electrical properties ofthe top electrode using a plurality of metal bumps coupled to the firsttop conductive features.
 9. The method of claim 1, further comprisingmeasuring electrical properties of the bottom electrode using aplurality of metal bumps coupled to the first bottom conductivefeatures.
 10. A method for forming a semiconductor device, the methodcomprising: forming a plurality of MiM capacitors, each of the MiMcapacitors having a bottom electrode, a top electrode, and a dielectriclayer interposed between the bottom electrode and the top electrode,each of the bottom electrodes being discontinuous from the bottomelectrodes of other MiM capacitors; forming one or more bottom contactinterconnects, each bottom contact interconnect electrically couplingbottom electrodes of adjacent MiM capacitors, the one or more bottomcontact interconnects being completely covered by a dielectric material;forming a first top contact electrically coupled to a first topelectrode of a first MiM capacitor of the plurality of MiM capacitors;and forming a first bottom contact contacting at least one of the bottomelectrodes from a top electrode direction, the first bottom contactbeing distinct from the one or more bottom contact interconnects. 11.The method of claim 10, wherein the plurality of MiM capacitors includea second MiM capacitor, further comprising forming a second top contactelectrically coupled to a second top electrode of the second MiMcapacitor.
 12. The method of claim 11, further comprising measuringelectrical properties between the first top contact and the second topcontact.
 13. The method of claim 12, further comprising measuringelectrical properties between the first top contact and the first bottomcontact.
 14. The method of claim 11, further comprising forming a secondbottom contact contacting at least another one of the bottom electrodesfrom the top electrode direction, the second bottom contact beingdistinct from the one or more bottom contact interconnects.
 15. A methodfor forming a semiconductor device, the method comprising: forming afirst MiM capacitor over a substrate; forming a second MiM capacitorover the substrate, each of the first MiM capacitor and the second MiMcapacitor having a top electrode and a bottom electrode; forming adielectric layer over the first MiM capacitor and the second MiMcapacitor; forming a plurality of first vias through the dielectriclayer to one of the top electrode of the first MiM capacitor and thebottom electrode of the first MiM capacitor; and forming a single secondvia to the other of the top electrode of the first MiM capacitor and thebottom electrode of the first MiM capacitor.
 16. The method of claim 15,wherein at least one the plurality of first vias extend to aninterconnect, and further comprising forming a third via extending fromthe interconnect to the second MiM capacitor.
 17. The method of claim16, wherein the third via extends to the top electrode of the second MiMcapacitor.
 18. The method of claim 16, wherein the third via extends tothe bottom electrode of the second MiM capacitor.
 19. The method ofclaim 15, wherein the second via extends through the top electrode ofthe first MiM capacitor.
 20. The method of claim 10, wherein forming thefirst top contact and forming the first bottom contact comprises:forming one or more first dielectric layers over the first topelectrode; forming at least one first opening to the first top electrodeand at least one second opening to the first bottom electrode; forming asecond dielectric layer in a lower portion of the first opening and thesecond opening, an upper surface of the second dielectric layer beingrecessed from an upper surface of the one or more first dielectriclayers; widening an upper portion of the first opening and the secondopening while the second dielectric layer is in the lower portion of thefirst opening and the second opening; removing the second dielectriclayer from the first opening and the second opening; and filling thefirst opening and the second opening with a conductive material.